Simplifying (super-)BMS algebras

Abstract

We show that the non-linear BMS${}_5$ symmetry algebra of asymptotically flat Einstein gravity in five dimensions, as well as the super-BMS${}_4$ superalgebra of asymptotically flat supergravity, can be redefined so as to take a direct sum structure. In the new presentation of the (super-)algebra, angle-dependent translations and angle-dependent supersymmetry transformations commute with the (super-)Poincaré generators. We also explain in detail the structure and charge-integrability of asymptotic symmetries with symmetry parameters depending on the fields (through the charges themselves), a topic relevant for nonlinear asymptotic symmetry algebras.

23 pages, no figures